Silent letter

Silent letter
In an alphabetic writing system, a silent letter is a letter that, in a particular word, does not correspond to any sound in the word's pronunciation. In linguistics, a silent letter is often symbolised with a null sign . Null is an unpronounced or unwritten segment. The symbol resembles the Scandinavian letter Ø and other symbols.
English
One of the noted difficulties of English spelling is a high number of silent letters. Edward Carney distinguishes different kinds of "silent" letters, which present differing degrees of difficulty to readers.
Auxiliary letters which, with another letter, constitute digraphs, i.e. two letters combined which represent a single phoneme. These may further be categorized as:
"Exocentric" digraphs, where the sound of the digraph is different from that of either of its constituent letters. These are rarely considered "silent". Examples:
Where the phoneme has no standard single-letter representation, as with consonants for as in sing, for as in thin or as in then, diphthongs in out or in point. These are the default spellings for the relevant sounds and present no special difficulty for readers or writers.
Where standard single-letter representation uses another letter, as with in enough or in physical instead of . These may be considered irregular for writers, but less difficult for readers.
"Endocentric" digraphs, where the sound of the digraph is the same as that of one of its constituent letters. These include:
Most double consonants, as in clubbed; though not geminate consonants, as in misspell. Doubling due to suffixation or inflection is regular; otherwise, it may present difficulty to writers (e.g. accommodate is often misspelled), but not to readers.
Many vowel digraphs, as in leave (cf. accede), achieve, eulogy (cf. utopia).
The discontiguous digraphs, whose second element is "magic e", e.g. in rate (cf. rat), in fine (cf. fin). This is the regular way to represent "long" vowels in the last syllable of a morpheme.
Others, such as (which is in effect the "doubled" form of ), as in guard, vogue; as in bread, heavy, etc.; , as in aerial, oedipal. These may be difficult for writers and sometimes also for readers.
Dummy letters with no relation to neighboring letters and no correspondence in pronunciation:
Some are inert letters, which are sounded in a cognate word: e.g. in damn (cf. damnation); in phlegm (cf. phlegmatic); in practically (cf. practical); in ballet (cf. balletic). If the cognate is obvious, it may aid writers in spelling, but mislead readers in pronunciation.
The rest are empty letters, which never have a sound, e.g., in honor, in answer, in Sarah, in island, in subtle. These may present the greatest difficulty to writers and often to readers, as well.
The distinction between "endocentric" digraphs and empty letters is somewhat arbitrary. For example, in such words as little and bottle, one might view as an "endocentric" digraph for , or view as an empty letter; similarly, with or in buy and build.
Not all silent letters are completely redundant:
Silent letters can distinguish between homophones, e.g. in/inn; be/bee; lent/leant. This is an aid to readers already familiar with both words.
Silent letters may give an insight into the meaning or origin of a word; e.g. vineyard suggests vines more than the phonetic *vinyard would.
Silent letters may help the reader to stress the correct syllable (compare physics to physiques). The final in giraffe gives a clue to the second-syllable stress, where *giraf might suggest initial-stress.
Silent letters arise in several ways:
Sound changes occurring without a spelling change. The digraph was pronounced in Middle English in such words as light.
Sound distinctions from foreign languages may be lost, as with the distinction between smooth rho (ρ) and roughly aspirated rho (ῥ) in Ancient Greek, represented by and in Latin, but merged to the same in English.
Clusters of consonants may be simplified, producing silent letters; e.g. silent in asthma, silent in Christmas (in conservative RP, such as that spoken by Dame Vera Lynn, the is pronounced /krɪstməs/, as opposed to /krɪsməs/ in all other dialects). Similarly, with alien clusters, such as Greek initial in psychology and in mnemonic, and the much rarer clusters in chthonic and phthalate.
Compound words are often simplified in pronunciation, while their spelling remains the same. For example, cupboard and breakfast were once pronounced as written, but were then simplified over time. The words forehead and waistcoat have largely reverted to their spelling pronunciations, but were once pronounced *forrid and *weskit, respectively.
Occasionally, spurious letters are consciously inserted in spelling to reflect etymology (real or imagined). The in debt and doubt (from French dette, doute) was inserted to match Latin cognates like debit and dubitable. A silent was inserted in isle (Norman French ile, Old French isle, from Latin insula; cognate to isolate) and then extended to the unrelated word island. The in ptarmigan was apparently suggested by Greek words such as pteron ('wing').
Since accent and pronunciation differ, letters may be silent for some speakers, but not others. In non-rhotic accents, is silent in such words as hard, feathered; in h-dropping accents, is silent. A speaker may or may not pronounce in often, the first in Antarctic, in sandwich, etc.
Differences between British English and American English
Pronunciation
In the US, the h in herb is silent (an herb), but in the UK, it is pronounced (a herb). The same is true for the l in solder.
In parts of the UK, the a in dictionary and secretary is silent, but in the US, it is pronounced.
Spelling
In US spellings, silent letters are sometimes omitted (e.g., acknowledgment / UK acknowledgement, ax / UK axe, catalog / UK catalogue, program / UK programme outside computer contexts), but not always (e.g., dialogue is the standard spelling in the US and the UK; dialog is regarded as a US variant; the spelling axe is also often used in the US). In most words, silent letters are written in both styles (e.g., debt, guard, house).
Other Germanic languages
Danish
The Danish language has different letters that can be silent.
The letter is silent in the conjunction af.
The letter is silent in the conjunctions og and også.
The letter is silent in most dialects if followed by , as in hvad (‘what’), hvem (‘who’), hvor (‘where’).
The letter is silent at the end of words if preceded by , as in selv ('self'), halv ('half').
The letter is usually (but not necessarily) silent if preceded by a consonant, as in en mand (‘a man’), blind (‘blind’). Many words ending in are pronounced with a stød, but it is still considered a silent letter.
Faroese
The Faroese language has two silent letters.
The letter is almost always silent. It is rendered in orthography for historical reasons (e.g. 'father' , cf. Old Norse ). In some cases, however, the letter is pronounced , as in 'the weather' .
The letter (i.e. continuant of Old Norse ) is usually silent between vowels or when following a vowel before a pause (e.g. 'day' , cf. Old Norse ; 'I' , cf. Old Norse ). Use of the silent letter in Faroese is the same as for the letter edd - it is written for historical reasons as Faroese orthography was based on normalised spelling of Old Norse and Icelandic language.
Both Faroese silent letters and are replaced by a hiatus glide consonant (or ) when followed by another (unstressed) vowel.
German
In German, silent letters are rare apart from word-internal and the digraph .
Silent h is used in German to indicate vowel length or hiatus. This h is almost regularly added at the end of inflectable word stems, e.g. Kuh (cow), Stroh (straw), drehen (to turn, stem dreh-). There is only a fairly small number of exceptions to this, mostly nouns in -ee or -ie (see below), apart from isolated cases such as säen (to sow).
Otherwise silent h may be written before the letters l, m, n, r as in nehmen (to take), Stuhl (chair), Zahn (tooth). This latter use is highly irregular, however, and there are just as many words where the h is missing.
Historically, this use of silent h goes back to the Middle High German consonant , which became silent in words like sehen (to see), zehn (ten). By analogy it was then also used in words that had no such h in Middle High German. The majority of silent h’s in modern German are analogical rather than etymological.
The long i-sound is usually written , with a silent , as in viel (much), spielen (to play), Wien ('Vienna'), and hundreds of other words.
In native German words this spelling is fairly unambiguous. Some words of foreign origin also behave like native words, e.g. Kurier, Papier, Turnier and all verbs ending (e.g. appellieren, organisieren).
In other foreign words, however, the after may be pronounced, e.g. Ambiente, Hygiene, Klient, or names like Daniela, Gabriel, Triest.
Words ending in can be particularly tricky to learners: There are generally two possibilities: (1.) when the final is stressed, it represents long as in Zeremonie ; (2.) when the preceding vowel is stressed, represents the separate vowels as in Folie .
To the first group belong e.g. Akademie, Allergie, Amnesie, Amnestie, Apathie, Artillerie, Batterie, Blasphemie, Chemie, Chirurgie, Demokratie, Energie, Epidemie, -gamie, Garantie, Genie, Geometrie, -grafie/-graphie, Harmonie, Hysterie, Infanterie, Ironie, Kavallerie, Kompanie, Kopie, -logie, Liturgie, Magie, Manie, Marie, Melodie, Monotonie, Nostalgie, Orthopädie, Partie, Phantasie, Philosophie, Poesie, Psychiatrie, Rhapsodie, Sinfonie, -skopie, Theorie, Therapie, Utopie.
To the second group belong e.g. Akazie, Aktie, Amalie, Begonie, Emilie, Familie, Folie, Geranie, Grazie, Hortensie, Hostie, Immobilie, Kastanie, Komödie, Kurie, Lilie, Linie, Orgie, Otilie, Pinie, Serie, Studie, Tragödie, Zäzilie.
Note that in female names there is a third category of words stressed on the antepenult, where also represents , e.g. Amelie, Leonie, Nathalie, Rosalie, Stefanie, Valerie (all stressed on the first syllable).
A special case arises when the after is a grammatical ending. In this case it is always pronounced. Therefore Zeremonie becomes Zeremonien in the plural, and the same is true of all other nouns in group 1 above. The noun Knie is pronounced when it is singular, but usually when it is plural. Spermien is plural of Spermium, hence also with a pronounced . Country names in -ien can also be joined to this group: Australien, Brasilien, Indien, Kroatien, Serbien, Slowenien.
Other letters
Other silent letters occur mainly in borrowings from French and other modern languages, e.g. Porträt (portrait), Korps (corps).
Informally, the letter may be silent in function words like ist (is), jetzt (now), nicht (not), and otherwise in clusters like Gedächtnis (memory), Kunststück (piece of art). These t’s are commonly silent in everyday speech, but will be retained in careful, formal parlance.
Romance languages
French
Silent letters are common in French, including the last letter of most words. Ignoring auxiliary letters that create digraphs (such as and , and and as signals for nasalized vowels), they include almost every possible letter except and .
Vowels
Final is silent or at least (in poetry and song) a nearly-silent schwa ; it allows the preservation of a preceding consonant, often allowing the preservation of a grammatical distinction between masculine and feminine forms in writing, e.g., in vert and verte (both ‘green’); the is pronounced in the latter (feminine) but not the former. Furthermore, the schwa can prevent an awkward ending of a word ending in a consonant and a liquid (peuple, sucre).
After or , a final is silent. The spelling is pronounced just the same as that for and is entirely an etymological distinction, so in that context, the is silent.
The digraph , used to represent before the front vowels and , has a silent . In contrast, the u is pronounced in .
for has the same silent before and . When the is not silent it must be marked with a trema: . Before and , the is not silent.
Consonants
is silent outside of the digraph and loanwords such as hat or hate. Numerous doubled consonants exist; French does not distinguish doubled consonants from single consonants in pronunciation as Italian does. A marked distinction exists between a single and doubled : doubled is always voiceless , while an intervocalic single is voiced .
The nasal consonants and when final or preceding a consonant ordinarily nasalize a preceding vowel but are not themselves pronounced (faim, tomber, vin, vendre). Initial and intervocalic and , even before a final silent , are pronounced: aimer, jaune.
Most final consonants are silent, usual exceptions to be found with the letters , and (the English word careful is mnemonic for this set). But even this rule has its exceptions: final is usually pronounced /e/ (=) rather than the expected /ɛʀ/. Final is silent after even in a diphthong (œil, appareil, travail). Final -ent is silent as a third-person plural verb ending, though it is pronounced in other cases.
Final consonants that might be silent in other contexts (finally or before another consonant) may seem to reappear in pronunciation in liaison: ils ont "they have", as opposed to ils sont "they are"; liaison is the retention (between words in certain syntactic relationships) of a historical sound otherwise lost, and often has grammatical or lexical significance.
Italian
The letter most often marks a / as hard (velar), as in spaghetti and scherzo, where it would otherwise be soft (palatal), as in gelato and cello, because of a following front vowel (or ).
Conversely, to soften or (to or respectively) before a back vowel, a silent is inserted: , etc. When in that position is not silent, it must be marked with a trema: . Before any other letter, or at the end of a word, the is not silent.
Silent is also used in forms of the verb avere ('have') – ho, hai and hanno – to distinguish these from their homophones o ('or'), ai ('to the') and anno ('year'). The letter is also silent at the beginning of words borrowed from other languages, such as hotel.
Spanish
Despite being rather phonemic, Spanish orthography retains some silent letters:
is silent outside of the digraph and loanwords such as hámster or hachís.
The digraph , used to represent before the front vowels and , has a silent . In contrast, the u is pronounced in .
for has the same silent before and . When the is not silent it must be marked with a trema: . Before and , the is not silent.
Intervocalic can be silent in relaxed speech.
Syllable onsets like are usually pronounced without p. In some but not all cases, this is reflected in the orthography that allows double forms with and without : ("tire"), / ("psychology"), / ("pterodactyl"). Reducing an internal (instead of , "concept") is not recommended except in ("September") and / ("seventh").
An internal may be pronounced with a silent . In some cases, this is considered vulgar; in others, it is the most common pronunciation and reflected in the orthography: ("substance")
Intervocalic or final can be weakly pronounced or silent depending on formality and dialect: , ("tired").
Greek
In Greek the comma also functions as a silent letter in a handful of words, principally distinguishing (ó,ti, "whatever") from (óti, "that").
Slavic languages
Czech
In the vast majority of cases, Czech pronunciation follows the spelling. There are only four exceptions:
D
For example: dcera (daughter) and in srdce (heart)
/j/ + consonant clusters in some words
In most present forms of the verb být ("to be"), namely jsem, jsi, jsme, jste and jsou (i.e. all persons but the 3rd person singular je), the initial cluster /js/ is regularly simplified to a mere /s/. This pronunciation is considered correct and neutral when the verb is unstressed and used as an auxiliary. When stressed or used lexically, only the full /js/ pronunciation is considered correct. In casual speech, however, a few other highly frequent words commonly undergo similar simplification, namely all present forms of jít ("to walk") beginning with /jd/ (that is jdu, jdeš, jde, jdeme, jdete, jdou), the noun jméno ("name") and the verb jmenovat (se) ("to name, to (be) call(ed)").
Russian
Several words in Russian omit written consonants when spoken. For example, "чувствовать" (chuvstvovat') is pronounced [ˈt͡ɕustvəvətʲ] and "солнце" (solntse) is pronounced [ˈsont͡sə].
Russian letter ъ has no phonetic value and functions as a separation sign. Before the spelling reform of 1918 this hard sign was written at the end of each word when following a non-palatal consonant.
Semitic languages
In Hebrew, almost all cases of silent letters are silent aleph – א. Many words that have a silent aleph in Hebrew, have an equivalent word in Arabic language, that is written with a mater lectionis alif –ا ; a letter that indicates the long vowel "aa". Examples:
The Hebrew word for "no" is לֹא (sounds like "lo", spelled like "loa") and the Arabic word for "no" is لاَ (sounds and spelled like "laa").
The Hebrew word for "left side" is שְׂמֹאל (sounds like "smol", spelled like "smoal") and the Arabic word for "north" is شَمَال (sounds and spelled like "shamaal").
The Hebrew word for "head" is רֹאשׁ (sounds like "rosh", spelled like "roash") and the Arabic word for "head" is رَأس (sounds and spelled like "ra's").
The explanation for this phenomenon is that the Hebrew language had a sound change of all the mater lectionis aleph letters into silent ones (see Canaanite shift). Due to that sound change, in Hebrew language, there are only two kinds of aleph - the glottal stop (/ʔ/) and the silent one, while in Arabic language all three kinds still exist.
The silent Arabic alif is marked with a wasla sign above it (see picture), in order to differentiate it from the other kinds of alifs. An Arabic alif turns silent, if it fulfils three conditions: it must be in a beginning of a word, the word must not be the first one of the sentence, and the word must belong to one of the following groups:
Verbs that start with the prefix "ʔi-", due to their conjugation and derived stem.
Ten specific nouns that begin with "ʔ":اسم, است, ابن/ابنة, اثنان/اثنتان, امرؤ/امرأة, اَيمن الله/اَيْم الله. Some of these words have a Hebrew word equivalent, and that equivalent had totally lost the beginning aleph. Examples: اسم (ʔism), meaning "a name" (in Maltese the word isem), sounds like "ism" if it is in the beginning of the sentence and "sm" if not; its Hebrew equivalent is שֵׁם (shem). إبن (ʔibn) (in Maltese the word iben), meaning "a son", sounds like "ibn" if it is in the beginning of the sentence and "bn" if not; its Hebrew equivalent is בֵּן (ben), in Maltese bin.
The alif of the word اَل (ʔal), meaning "the" - sounds like "al" if it is in the beginning of the sentence and "l" if not.
Besides the alif of the Arabic word ال (ʔal, meaning "the"), its lām (the letter L) can also get silent. It gets silent if the noun that word is related to, starts with a "sun letter". A sun letter is a letter that indicates a consonant that is produced by stopping the air in the front part of the mouth (not including the consonant M). The Hebrew equivalent to the Arabic word ال (ʔal, meaning "the") had totally lost its L.
In Maltese għ can be silent e.g. għar - meaning cave - and pronounced "ahr", or a voiced HH if it is followed by the or if it is at the end of a word e.g. qlugħ (q-glottal stop: ).
Uralic languages
The Estonian and Finnish languages use double letters for long vowels and geminate consonants.
Turkish
In the Turkish language, often has no sound of its own, but lengthens the preceding vowel, for example in dağ ("mountain") . In other surroundings, it may be pronounced as a glide.
Persian
In Persian, there are two instances of silent letters:
The letter he after a short vowel, unless in a monosyllabic word, has no sound of its own. It is only written because according to spelling rules a word cannot end in a short vowel.
The Silent Vav is always written but not spoken in Standard Persian. It used to represent the labialization of the voiceless velar fricative, which no longer exists in the standard dialect, making it an archaic remnant of the old standards of pronunciation.
Indic languages
Unconventional to Sanskrit and Proto-Indo-European root languages, some Indic languages have silent letters. Among Dravidian languages, Tamil and Malayalam have certain distinct styles of keeping few of their letters silent. Among the Indo-Aryan languages, Bengali language has silent letters.
Tamil
Tamil is a classical language phonetically characterized by allophones, approximants, nasals and glottalised sounds. Some words, however, have silent letters in them. The words அஃது (while that is), and அஃதன் (that) contain the Āytam or '', which is not pronounced in Modern Tamil. It is explained in the Tolkāppiyam that āytam could have glottalised the sounds it was combined with, though some may argue it sounded more like the Arabic ''. That being said, modern words like ஆஃபிஸ் (Office) use '' and '' in sequence to represent the sound, as the āytam is nowadays also used to transcribe it and other foreign phonemes.
Another convention in Middle Tamil (Sen-Tamil) is the use of silent vowels to address a mark of respect when beginning proper nouns. The Ramayana was one such text where the word Ramayana in Tamil always began with '', as in இராமாயணம், though it was not pronounced. The name கோபாலன் was so written as உகோபாலன் prefixed with an ''.
Malayalam
Inheriting elision, approximants and allophones from Tamil, in Malayalam, except for Sanskrit words, words ending in the vowel '' become silent at the end and if not compounded with words succeeding them, replace the '' vowel by the schwa . However, it is considered disrespectful to change this pronunciation in the simple present verbs, when using imperatives and using what can be termed as Imperative-Active voice in Malayalam, where the second person is respectfully addressed with his or her name instead of നീ (you) or നിങ്ങൽ (yourselves). For example, in the sentence, രാകേശ് പണി തീർക്കു (Rakesh, finish your work), the use of the second personal pronoun is avoided with the name രാകേശ് (Rakesh), but this sentence sounds less respectful if the '' in തീർക്കു (finish} is replaced by the schwa or , as in "തീർക്കു!" (, Finish!) which sounds like an order. Notice the at the end of the name Rakesh which is pronounced after being added to the Sanskritic name.
Bengali
Unlike other Indic languages, Bengali, features silent consonants, which occur in many consonant clusters. These silent letters usually occur in loanwords borrowed from Sanskrit. These silent letters occur due to sound mergers as the spellings of Sanskrit loanwords have been preserved but their pronunciation has changed with sound mergers.
The letter 'ব' ('b') is silent in most of the consonant clusters where it occurs as the second one. For example, "স্বপ্ন "(স্ব = স্ 'sh' + ব ) (dream) is written as "shbôpno" but pronounced as "shôpno".
"জ্বর" (জ্ব = জ্ 'j' + ব )(fever) is written as "jbôr" but pronounced as "jôr". This is the case with consonant clusters at the beginning of the words.
If the consonant cluster occurs in the middle or at the end of a word, the 'ব' serves as a marker to put stress on the first consonant in a consonant cluster. For example , "বিশ্বাস" (শ্ব = শ্ 'sh' + ব) (to believe ) is written as " bishbāsh" but pronounced as " bishāsh" with more stress on the sh than usual, which sounds like "bishshāsh".
The letter 'ম'('m') also remains silent in many consonant clusters where the consonant cluster occurs at the beginning of the word. For example, "স্মৃতি" (স্মৃ = স্ 's' + ম + ঋ 'ri' )(memory) is written as "smriti" but pronounced as "sriti". In many cases, if the consonant cluster occurs in the middle of a word, then the preceding vowel should be nasalised and the first letter in the cluster is stressed and 'ম' in the cluster is silent. For example, " আত্মা" (ত্মা = ত্ 't' + মা 'mā'), i.e., "ātmā" (soul) is pronounced as "āttā" and the ' ā ' is nasalised.
The letter 'য় ('y') is also silent in many cases as in "মেয়ে" (য়ে = য় + এ 'ē')(girl ) is written as " mēyē " but pronounced as "mē" .
The letter 'য' ('j') in its consonant clusters changes the pronunciation of the other letters in the cluster. For example, ন্যায় (ন্যা = ন 'n'+ য + আ 'ā')(justice) is written as "njāy" but pronounced as "nay" (a as in hat) or in কন্যা (girl or daughter) written as "konja" but pronounced as "konna".But sometimes, it is completely silent as in সন্ধ্যা (ন্ধ্যা = ন্ 'n' + ধ 'dh' + য + আ 'ā') (evening) is written as "shondhjā" but pronounced as "shondhā".
Moreover, Bengali also features schwa deletion common to other Indo-Aryan languages, where the schwa, 'o' or 'ô' is omitted while pronounciation, for example, "কাকতলা" (incident) is written as "kākotôlā" but pronounced as "kāktôlā".
Similarly, in many other consonant clusters, the second consonant is silent.
Zhuang-Tai languages
Thai
Thai has a deep orthography like English and French. Unlike the two languages, however, the Thai script is an abugida rather than a true alphabet. Nonetheless, silent consonants, vowels, and even syllables are common in Thai. Thai has many loanwords from Sanskrit and Pali, and rather than spell aforementioned words according to Thai phonics, the script tends to maintain the etymological spellings. For example, a romanization of the word ประโยชน์ that reflects Thai orthography is , but it would be pronounced as , where the extra letter for -n is completely silent. Another example is the Thai word มนตร์, which is sometimes written as mantra like it would be in Sanskrit, but it is only pronounced in Thai. Though the second syllable is pronounced in Sanskrit, it is completely absent when pronouncing the word in Thai. In such words, the diacritic , known as , is used to mark silent letters.
Also, different letters can be used for the same sound (for example, [tʰ] can be spelled as , or ) depending on which class the consonant is, which is important for knowing which tone the syllable will have, and whether or not it is a loanword from Sanskrit or Pali. However, some letters written before low class consonants become silent and turn the low class syllable into a high class one. For example, even though the high class letter is used to write the sound /h/, if the letter comes before a low class letter in a syllable, the letter will become , which will make the letter silent and it will turn the syllable into a high class syllable. For example, the word is a low class syllable because its initial consonant is a low class consonant. The syllable is pronounced (with a long vowel and mid tone) and it means "field". However, the word is a high class syllable, despite it containing a low class consonant in the onset. The syllable is pronounced (with a long vowel and a rising tone) and it means "thick".
Lao
Like Thai, Lao also has a letter that becomes silent if it comes before a low class consonant. The letter is ho sung ຫ, which would represent the sound /h/ if it were not paired with another low class consonant. However, unlike Thai, the digraphs beginning with the aforementioned letter can sometimes be written as a ligature.
Zhuang
In the standard Zhuang language, written in the Latin script, the last letter of every syllable is typically silent due to it representing the tone of the syllable. The digraphs mb and nd also have silent letters, representing the phonemes ɓ and ɗ respectively.
Korean
In the Hangul Orthography of the Korean language, the letter ⟨ㅇ⟩ is silent when written in the syllable-initial position, and represents the sound /ŋ/ when written in the syllable-final position. For example, in the word 안녕 (Yale Romanization: ) (meaning "hello"), composed of the letters "ㅇㅏㄴㄴㅕㅇ", the first ⟨ㅇ⟩ is silent, and the last ⟨ㅇ⟩ is pronounced as /ŋ/. The reason for this can be found in 15th-century Hangul orthography. In the 15th century, the letter ⟨ㅇ⟩ originally represented /∅~ɣ/ (a lenited form of ㄱ /k/), while the letter ⟨ㆁ⟩ unconditionally represented /ŋ/. But because in Middle Korean phonology, ⟨ㆁ⟩ was not allowed in syllable-initial position, and ⟨ㅇ⟩ was not allowed in syllable-final position, it formed a complementary distribution of the two letters. Because of this and due to the fact that the letters look very much alike, the two letters merged.
Korean's syllable structure is CGVC, and Korean's writing system, Hangul, reflects this structure. The only possible consonant cluster in a single syllable must contain a glide and they must occur in the onset. However, sometimes a cluster of two consonants are written after the vowel in a syllable. In such situations, if the next syllable begins with a vowel sound, then the second consonant becomes the first sound of the next syllable. However, if the next syllable begins with a consonant sound, then one of the consonants in the cluster will be silent (sometimes causing fortition in the following consonant). For example, the word 얇다 (meaning "thin") is written as (Yale: yalp.ta), but the word is pronounced as if it was written yal.tta because the second syllable begins with a consonant sound. However, the word 얇아서 (also meaning "thin") is written as (Yale: yalp.a.se) and it is pronounced as yal.pa.se because the second syllable begins with a vowel sound.
Mongolian
Interestingly, the native Mongolian script has much more orthographic depth than Mongolian Cyrillic. For example, the letter Gh or γ (ᠭ) is silent if it is between two of the same vowel letters. In that case, the silent consonant letter combines to two written vowel into one long vowel. For example, the Mongolian word Qaγan (ᠬᠠᠭᠠᠨ) should be pronounced Qaan (ᠬᠠᠠᠨ). In Mongolian Cyrillic, however, it is spelled хаан (haan), closer to the actual pronunciation of the word. Words in the Mongolian script can also have silent vowels as well. For Mongolian name of the city Hohhot, it is spelled Kökeqota (ᠬᠥᠬᠡᠬᠣᠲᠠ) in Mongolian script, but in Cyrillic, it is spelled Хөх хот (Höh hot), closer towards the actual pronunciation of the word.
Basque
In Basque, during the 20th century was not used in the orthography of the Basque dialects in Spain but it marked an aspiration in the North-Eastern dialects. During the standardization of Basque in the 1970s, the compromise was reached that would be accepted if it were the first consonant in a syllable. Hence, ("people") and ("to come") were accepted instead of (Biscayan) and (Souletin). Speakers could pronounce the h or not. For the dialects lacking the aspiration, this meant a complication added to the standardized spelling.
See also
Apheresis (linguistics)
Elision
List of names in English with counterintuitive pronunciations, many with multiple silent letters.
Schwa deletion in Indo-Aryan languages, explains rules of Modern Indo-Aryan languages that delete the schwa sound.
Silent e
Silent k
Syncope (phonology)
Three-letter rule, the source of some common English silent letters.
References
Spelling
English orthography
Letter